If I were a Springer-Verlag Graduate Text in Mathematics, I would be J.-P. Serre's A Course in Arithmetic.
Jean-Pierre Serre is Professor at the College de France. He has written a number of books, including "Algebraic Groups and Class Fields", "Local Fields", "Complex Semisimple Lie Algebras", "Linear Representations of Finite Groups", Collected Papers (3 volumes), and "Trees" published by Springer-Verlag.
Which Springer GTM would you be? The Springer GTM Test